In recent years, in the fields of electronic devices, long-term reliability, high degree of freedom in shape, and the capability of a curved surface display have been added to the demands for larger and lighter electronic devices. A resin base material such as transparent plastics has begun to be adopted instead of a glass substrate that is heavy, fragile, and that has difficulty in upsizing.
However, there is a problem that a resin base material such as transparent plastics has inferior gas barrier properties to a glass substrate. It is known that the use of a substrate having inferior gas barrier properties allows permeation of water vapor and oxygen, and thus deteriorates the function of, for example, an electronic device.
Accordingly, it has been generally known that there is used a gas barrier film obtained by formation of a film having gas barrier properties (gas barrier layer) on a resin base material. There is proposed the formation of a gas barrier layer including an organic layer arranged between, for example, an inorganic layer and an inorganic layer, on the resin base material (refer to, for example, Patent Literature 1).
Furthermore, in the organic electroluminescent (EL) element that is one of the electronic devices, it has been known that a configuration of providing a light extraction layer including a light scattering layer is effective in order to enhance the light emission efficiency.
However, when the gas barrier layer and a scattering layer are formed on a resin base material, the surface has unevenness, and when an organic functional layer having a light-emitting layer is formed thereon, the obtained element has problems that preservability under a high temperature and humidity is deteriorated, and short circuit (electric short-circuiting) becomes easily generated.
Furthermore, when the light extraction layer is formed on the resin base material, impurities remaining on the light extraction layer and the gas barrier layer produce bad influences on the organic functional layer. It has been primarily known that the organic EL element has high sensitivity to a slight amount of water/oxygen/other organic substances (remaining solvent, and the like), and thus there is also proposed a configuration of having a gas barrier layer just below the organic functional layer (refer to, for example, Patent Literature 2).